A disk drive having a motor and a velocity control loop, which includes a frequency detector and a filter. The filter includes a filter section and an accumulator. The filter is programmable in that filter coefficient(s) are dynamically received by the filter section. One embodiment of the filter section is an infinite impulse response filter. One embodiment of the filter is a digital integrated circuit. A method for compensating a control loop by infinite impulse response filtering and accumulating. The control loop may be a position, velocity, acceleration or force control loop. A programmable digital integrated circuit for compensating a velocity control loop having a filter section cascaded with an accumulator. The integrated circuit may include memory for storing filter coefficient(s) for the filter section, thereby not requiring external components.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A disk drive comprising: a motor for spinning a disk, the motor having input terminals for receiving control signals; a control loop for controlling the motor, the control loop comprising: an input terminal for receiving a reference control signal; an output terminal for providing a feedback signal from the motor, the feedback signal being indicative of operating characteristics of the motor; means for generating an error signal based upon the reference control signal and the feedback signal, the means having a plurality of input terminals, the input terminal of the velocity control loop being connected to a first input terminal of the means and the output terminal of the velocity control loop being connected to a second terminal of the means, the means further having an output terminal to carry the error signal; a filter being at least a second order filter connected to the output terminal of the means, the filter comprising: a filter section being one order below the filter, the filter section having an output terminal for supplying a first compensated signal; and an accumulator having an input terminal connected to the output terminal of the filter section and an output terminal electrically connected to an output terminal of the filter.
2. The disk drive according to claim 1 , wherein the filter comprises a digital integrated circuit.
3. The disk drive according to claim 1 , wherein at least one filter coefficient is received by the filter section, the filter section having a transfer function defined by the at least one filter coefficient.
4. The disk drive according to claim 3 , wherein the filter coefficients are digital values received from a bus connected to the filter.
5. The disk drive according to claim 1 , wherein the filter section is an infinite impulse response filter.
6. The disk drive according to claim 1 , wherein the disk drive is one of a plurality of storage devices operating within a network of storage devices.
7. The disk drive according to claim 1 , wherein the control loop is a velocity control loop.
8. The disk drive according to claim 1 , wherein the disk drive is included within a system, the system having a processor for performing computations and/or logical operations.
9. A control loop for controlling a motor, the control loop comprising: an input terminal for receiving a reference control signal; an output terminal for providing a feedback signal from the motor, the feedback signal being indicative of operating characteristics of the motor; means for generating an error signal based upon the reference control signal and the feedback signal, the means having a plurality of input terminals, the input terminal of the velocity control loop being connected to a first input terminal of the means and the output terminal of the velocity control loop being connected to a second terminal of the means, the means further having an output terminal to carry the error signal; a filter being at least a second order filter connected to the output terminal of the means, the filter comprising: a filter section being one order below the filter, the filter section having an output terminal for supplying a first compensated signal; and an input terminal for receiving at least one filter coefficient, the at least one filter coefficient defining a transfer function of the filter section; an acumulation having an input terminal connected to the output terminal of the filter section and an output terminal electrically connected to an output terminal of the filter.
10. The control loop according to claim 9 , wherein the filter coefficients are digital values received from a bus connected to the filter.
11. The control loop according to claim 9 , wherein the filter section is an infinite impulse response filter.
12. The control loop according to claim 9 , wherein the control loop includes at least one of the following control loops: a velocity control loop, a position control loop, an acceleration control loop, and a force control loop.
13. The control loop according to claim 9 , wherein the filter comprises a digital integrated circuit.
14. The control loop according to claim 9 , wherein the control loop is included within a disk drive.
15. A method for compensating a control loop within an automatic control system, the method comprising the steps of: receiving an error signal to be filtered; filtering the error signal, the filtering step comprising the steps of: performing an infinite impulse response filtering to generate a first compensated signal; and accumulating the first compensated signal to generate a second compensated signal; and outputting the second compensated signal, the second compensated signal being utilized for providing a control signal to a device being controlled by the control loop.
16. The method according to claim 15 , further comprising the steps of: dynamically receiving at least one filter coefficient; and defining filter characteristics for the infinite impulse response filtering-based upon the received at least one filter coefficient.
17. The method according to claim 15 , wherein the step of receiving the at least one filter coefficient is performed serially.
18. The method according to claim 15 , wherein the infinite impulse response filtering is a first-order infinite impulse response filtering.
19. The method according to claim 15 , wherein the control loop is at least one of the following: a position control loop; a velocity control loop; an acceleration control loop; or a force control loop.
20. A system comprising: a processor for performing computations and/or logical operations; and a motor for spinning a disk, the motor having input terminals for receiving control signals; a control loop for controlling the motor, the control loop comprising: an input terminal for receiving a reference control signal; an output terminal for providing a feedback signal from the motor, the feedback signal being indicative of operating characteristics of the motor; means for generating an error signal based upon the reference control signal and the feedback signal, the means having a plurality of input terminals, the input terminal of the velocity control loop being connected to a first input terminal of the means and the output terminal of the velocity control loop being connected to a second terminal of the means, the means further having an output terminal to carry the error signal; a filter being at least a second order filter connected to the output terminal of the means, the filter comprising: a filter section being one order below the filter, the filter section having an output terminal for supplying a first compensated signal; and an accumulator having an input terminal connected to the output terminal of the filter section and an output terminal electrically connected to an output terminal of the filter.
21. The system according to claim 20 , wherein the system includes at least one of the following: a computing device, an audio player; or a digital video disk player.
22. The system according to claim 20 , wherein the control loop is a velocity control loop.
23. The system according to claim 20 , wherein the filter comprises a digital integrated circuit.
24. The system according to claim 20 , wherein the filter section is defined by at least one filter coefficient, the at least one filter coefficient being a digital value received from a bus connected to the filter.
25. The system according to claim 20 , wherein the filter section includes an infinite impulse response filter.
26. An integrated circuit for processing a signal comprising: an input signal terminal for receiving an input signal; a filter section electrically connected to the input signal terminal, the filter section dynamically receiving at least one filter coefficient to compensate the input signal to produce a first compensated signal, the filter section further having an output terminal; an accumulator having at least one input terminal and an output terminal, the accumulator producing a second compensated signal, the output terminal of the filter section connected to the at least one input terminal of the accumulator; and an output terminal electrically connected to the output terminal of the accumulator for outputting the second compensated signal.
27. The integrated circuit according to claim 26 , wherein the integrated circuit is a digital integrated circuit.
28. The integrated circuit according to claim 26 , wherein the filter section further includes an infinite impulse response filter, the infinite impulse response filter being at least a first order filter.
29. The integrated circuit according to claim 26 , further comprising at least one storage element for storing the at least one filter coefficient.
30. The integrated circuit according to claim 26 , a bus.
31. The integrated circuit according to claim 26 , further comprising an analog to digital converter electrically connected between the input signal terminal and the filter section.
32. The integrated circuit according to claim 26 , further comprising a digital to analog converter electrically connected between the accumulator and the output terminal.
33. An apparatus comprising: means for receiving an input signal; and means for filtering the input signal, the means for filtering comprising: means for performing a first filtering of the input signal to create a first filtered signal; means for dynamically receiving at least one filter coefficient, the at least one filter coefficient being applied to the means for performing a first filtering; and means for performing a second filtering, the means for performing a second filtering receiving the first filtered signal.
34. A programmable digital integrated circuit for compensating a velocity control loop, the digital integrated circuit comprising: an input terminal for receiving an input signal; an output terminal for delivering a compensated input signal; a serial bus terminal for receiving filter coefficients provided in a digital format; a digital filter section having an input terminal, an output terminal, and a terminal for dynamically receiving coefficients, the input terminal of the filter section coupled to the input terminal of the integrated circuit, the filter section having dynamic characteristics defined by the coefficients received by the serial bus terminal; and an integrator having an input terminal coupled to the output terminal of the filter section and having an output terminal coupled to the output terminal of the integrated circuit.
35. The programmable digital integrated circuit according to claim 34 , wherein the filter section is a first order digital filter.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
July 25, 2000
September 2, 2003
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